Question 1008275
<pre>
There are only these 4 ways to arrange them sex-wise:

GBGBGB, BGBGBG, GBBGBG, GBGBBG

For each of these 4 sex-wise arrangements, there are

3! ways to arrange the 3 girls, and
3! ways to arrange the 3 boys.

That's 4*3!*3! = 4*6*6 = 144 ways.

Edwin</pre>